When to Plant Calendula in Whitehorse, YT
Calendula (Calendula officinalis) is a cheerful, edible-flowered cool-season annual valued by herbalists, chefs, and gardeners alike. Its golden-orange petals are used in salves, teas, and as a saffron substitute. Hardy enough to tolerate light frosts, it blooms prolifically in spring and fall, taking a pause during the hottest weeks of summer.
Whitehorse, Yukon is in USDA Zone 2b. The average last spring frost is June 15 and the first fall frost is September 30, giving you a growing season of approximately 107 days.
At an elevation of 2,316 feet, Whitehorse receives approximately 13 inches of rainfall annually with predominantly permafrost soil soil. Summer highs average 66°F, so choose short-season varieties of Calendula to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Calendula successfully. Mulch heavily to conserve soil moisture.
Whitehorse Soil Profile
Soil Type
Permafrost Soil
Soil pH
6.0-7.0
Drainage
Well Drained
Calendula Planting Risk Windows
Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.
How to Plant Calendula
Calendula Water Budget
Monthly Watering Guide for Calendula
Calendula needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.
| Month | Calendula Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 0.6" | 0" | ❄️ Dormant |
| Feb | — | 0.6" | 0" | ❄️ Dormant |
| Mar | — | 0.8" | 0" | ❄️ Dormant |
| Apr | — | 1.4" | 0" | ❄️ Dormant |
| May | — | 1.3" | 0" | ❄️ Dormant |
| Jun | 2.2" | 1.8" | 0.4" | 💧 Light watering |
| Jul | 2.2" | 1.3" | 0.9" | 💧 Light watering |
| Aug | 2.2" | 1.2" | 1" | 💧 Light watering |
| Sep | 2.2" | 1.3" | 0.9" | 💧 Light watering |
| Oct | — | 1" | 0" | ❄️ Dormant |
| Nov | — | 0.8" | 0" | ❄️ Dormant |
| Dec | — | 0.8" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Jun–Sep in Whitehorse). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Calendula Heat Requirements (GDD)
What are Growing Degree Days (GDD)?
Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.
Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.
Calendula Planting Timeline — Whitehorse, YT
Calendula Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 20 | Apr 20 – May 4 |
| Transplant Outdoors | June 15 | Jun 15 – Jun 29 |
| Direct Sow | June 15 | Jun 15 – Jul 6 |
| Bloom | August 3 | Aug 3 – Oct 5 |
Plant 0.3" deep · 9" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | Start Indoors |
| June | Transplant Outdoors Direct Sow |
| July | Direct Sow |
| August | Bloom |
| September | Bloom |
| October | Bloom |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.5"/week · Natural rainfall sufficient
📅 Days to Maturity
50–70 days
🧪 Soil pH
Needs 5.5–7 · Your soil: N/A
🗺️ USDA Zone
Zone 2b
📆 Growing Season
107 days in Whitehorse
Growing Tips for Calendula in Whitehorse
Common pests for Calendula in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.
Whitehorse receives only 13" of rain annually. Calendula needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
General growing tips
Direct-sow in early spring as soon as soil can be worked — seeds germinate in cool soil (50-65°F). In zones 7+, also sow in fall for winter/spring bloom. Deadhead consistently to extend bloom. Plants self-seed readily; save a few spent heads and allow them to drop. Harvest petals when flowers are fully open for best flavor and medicinal value.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Calendula in Other Locations
Frequently Asked Questions
When should I plant Calendula in Whitehorse, YT?
Whitehorse is in Zone 2b with an average last frost of June 15. Plan your Calendula planting based on this frost date — see the calendar above for exact timing.
What planting zone is Whitehorse, YT?
Whitehorse, Yukon is in USDA Hardiness Zone 2b. The average last spring frost is June 15 and first fall frost is September 30.
Your Whitehorse Garden Planner — Free
A 22-page printable planner built for Whitehorse (Zone 2b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.